We propose to locate and characterize fatty acid binding sites of serum albumin. Locations will be determined by affinity labeling techniques. Radioactive long-chain fatty acid derivatives will be chemically coupled to albumin at fatty acid binding sites. Labeled albumin will be cleaved and fragments carrying the affinity label will be isolated and identified by amino acid composition and sequence. Characterization of binding properties will include determination of the number of binding sites and empirical affinity constants describing the sites and investigation of interactions of the fatty acid binding sites with each other and with sites for other physiologically important ligands bound to and transported by albumin. Comparisons of properties of albumins from atherosclerotic patients and healthy control subjects will be made with the intent of identifying a possible role for albumin in the lipid metabolism and lipid deposition of atherosclerosis.